I've started a cutover migration and there are a few source mailboxes that are normal user mailboxes that need to be shared mailboxes in Office 365 so that they don't consume a license.
Even though we're still in the sychronisation phase I've changed the Office 365 mailboxes to type 'shared' and limited them to 5GB quotas (they're all less than that). Unfortunately they are still listed in the custom view “Users with Exchange mailboxes or archives and no licenses” which suggests they require a license.
I've created a new test shared mailbox in Office 365 and it doesn't show up in this view.
What will happen after the migration is complete? I'm worried that these mailboxes will be deleted at the end of the grace period as there are no licenses available for them. As far as I can tell they meet the criteria for unlicensed shared mailboxes. Is it just new shared mailboxes that are created in Office 365 (not migrated) that fulfil the criteria? How do other people deal with this?
Where's the documentation for this? I'm starting to get annoyed at the lack of detail in the Office 365 documentation...